Within the framework of the Flow Cytometry Network, we will participate in the 3 proposed studies, i.e. (1) To identify optimal methodology and interinstitutional procedures; (2) To share in the development and comparison of cell preparation techniques, flow cytometric analysis, data acquisition, interpretation and evaluation, and (3) to develop optimal techniques for analysis of voided urine specimens. Prior extensive histologic and cytologic studies of bladder cancer, as well as flow cytometric data on DNA distribution, strongly suggest that there are 2 distinct, although overlapping pathways of bladder neoplasia: the relatively innocuous papillary, mainly diploid, low grade tumors, and the flat carcinoma in situ (and high grade papillary tumors derived therefrom) which are aneuploid and have an ominous prognosis. It was also suggested that the proportion of tumor cells in S-phase may be of prognostic value. We further documented that the density of nuclear pores and expression of Ca antigen were significantly lower in diploid than in aneuploid tumors, several of which were invasive. Thus, we propose the following specific goals to be pursued: 1. To confirm that the assessment of tumor ploidy and the proportion of cells in S-phase in bladder washings are of diagnostic and prognostic value in bladder tumors. 2. To establish the reliability of flow cytometric data from bladder washings by comparison with DNA content of tissues from bladder tumors and with conventional cytologic and histologic observations in the same patients. 3. To determine the value of flow cytometric data as a replacement for cystoscopy in follow-up of patients with surgically treated tumors. 4. To determine the value of flow cytometry in monitoring of patients undergoing chemo- and immunotherapy (for example, with BCG). 5. To seek methods of processing of voided urine for flow cytometry for purposes of non-invasive and cost-effective monitoring of patients with bladder tumors and as a system of bladder cancer detection. 6. To evaluate new probes and procedures for flow cytometry for bladder tumors. The two overriding goals of these studies are: To seek objective uniform parameters leading to better evaluation, hence optimal treatment and follow-up of patients with bladder tumors and to provide a cost-effective, non-invasive laboratory procedure for bladder cancer diagnosis and detection.